The present invention relates to a novel anthrapyridone compound, a water-based magenta ink composition, and a method of ink-jet recording.
Diverse ink jetting processes have been developed for the recording method by means of ink-jet printer, and any process comprises generating ink droplets to deposit them onto various recording materials (such as paper, film, cloth) for recording. The recording method by means of ink-jet printer has rapidly been spread in recent years and will be propagated in future because the method brings about no noise due to the system in which a recording head does not contact with the recording material and because the method advantageously allows the printer to become downsized easily, to work in a high-speed and to give color printing. For recording an image information or a character information pictured on a computer color display in color by means of an ink-jet printer, the information is generally printed according to subtractive color mixing of inks of four colors, namely yellow(Y), magenta(M), cyan(C) and black(K). In order to print reproducibly an image pictured by additive color mixing of R, G ,B on a CRT display as faithfully as possible according to subtractive color mixing, the dyestuffs used, especially ones for a YMC ink, are desired to have color hues close to the respective standards of YMC (xe2x80x9cJapan Color Standard Paperxe2x80x9d published by Japan Printing Machinery Manufacturers Association) and vividness. Additionally, it is required that the resulting ink composition is stable for long-term storage and that the resulting printed image is of a high optical density and has excellent fastness including water fastness and light fastness. The present invention relates to a magenta ink.
Ink-jet printers are increasingly used in a wide range from a small one for OA to a big one for industrial use. So, excellence in fastness such as water fastness and light fastness of the printed image is more strictly demanded. The water fastness is substantially improved by coating inorganic micro particles such as porous silica, which can absorb dyestuff from ink, on a paper sheet with PVA resin. Various coated sheets for ink-jet printing are already available on the market. But light fastness is not yet improved by an established technique. Of tetrachromatic colors of YMCK, magenta especially has many dyestuffs which are naturally weak in light fastness, and the improvement is an important problem to be solved.
The chemical skeletal structure of magenta dyestuffs used in a water-soluble ink for ink-jet recording is represented by a xanthene type disclosed by JP Laid-Open No. 89811/1979, JP Laid-Open No. 60053/1996 and JP Laid-Open No. 143798/1996, or an azo type using- the H acid disclosed by JP Laid-Open No. 62562/1986, JP Laid-Open No. 156168/1987, JP Laid-Open No. 203970/1991, JP Laid-Open No. 157698/1995 and JP Publication No. 78190/1995. The xanthene type is indeed excellent in hue and vividness, but is inferior in light fastness. The azo type using the H acid is good in hue and water fastness, but is inferior in light fastness and vividness. As disclosed by JP Laid-Open No. 203970/1991, for example, some magenta dyestuffs being excellent in vividness and light fastness have been developed, but are still inferior in light fastness to the other hue dyestuffs such as yellow dyestuffs and cyan dyestuffs represented by copper phthalocyanine type.
Alternatively, for a chemical skeletal structure of magenta dyes excellent in vividness and light fastness, an anthrapyridone type is known as disclosed by JP Laid-Open No. 74173/1984 and JP Laid-Open No. 16171/1990, but can not yet show any satisfactory properties in hue, vividness, light fastness, water fastness and stability in solution.
A object of the present invention is to provide a water-based magenta ink composition which has a wide range of blend color in hue and vividness suitable for ink-jet recording and supplies the recorded material with a high fastness in light fastness and water fastness.
The present inventors made a diligent study to solve the above problem and, as a result, have completed the present invention. Namely, the present invention is as follows:
(1) An anthrapyridone compound represented by Formula A-B or the salt thereof, wherein A is the dyestuff residue represented by Formula (1) 
(In the formula, R1 is hydrogen atom ,an alkoxycarbonyl group or a benzoyl group and R2 is hydrogen atom or methyl group); and B is hydrogen atom or a substituent group on the dyestuff residue A.
(2) An anthrapyridone compound or the salt thereof according to term (1). wherein said B is an acyl group, a substituted or unsubstituted benzene sulfonyl group, a substituted or unsubstituted alkyl sulfonyl group, or a group represented by Formula (2) 
(In the formula, each X and Y is independently chlorine atom, hydroxyl group, amino group, monoethanolamino group, diethanolamino group, morpholino group or anilino group (which may have one or more substituent selected from the group consisting of sulfonate group, carboxyl group, methyl group and chlorine atom)).
(3) An anthrapyridone compound or the salt thereof according to term (2), wherein said X is anilino group (which may have one or more substituent selected from the group consisting of sulfonate group and-carboxyl group), and Y is chlorine atom, hydroxyl group, amino group, monoethanolamino group, diethanolamino group or morpholino group.
(4) An anthrapyridone compound or the salt thereof according to term (2), wherein B is benzene sulfonyl group, tosyl group, 2-carboxy-benzoyl group or 3,4-dicarboxy-benzoyl group.
(5) An anthrapyridone compound or the salt thereof according to term (1), wherein said R1 is hydrogen atom; R2 is methyl group.
(6) A water-based magenta ink composition which comprises containing the anthrapyridone compound or the salt thereof according to any one of term (1) to (5).
(7) A water-based magenta ink composition according to term (6), wherein said composition contains water and an organic solvent.
(8) A water-based magenta ink composition according to term (6) or (7), wherein the content of inorganic salt included in said anthrapyridone compound or the salt is 1% by weight or less.
(9) A water-based magenta ink composition according to any one of term (6) to (8), wherein said composition is prepared for ink-jet recording.
(10) A method for ink-jet recording which comprises using the water-based magenta ink composition according to any one of term (6) or (8) as an ink, in the recording way that ink droplets are ejected responding to record signals to record onto a recording material.
(11) A method for ink-jet recording which comprises using both the water-based magenta ink composition according to any one of term (6) or (8) as an magenta ink and a water-based ink containing water-soluble metal phthalocyanine dyestuff as a cyan ink, in the recording way that ink droplets are ejected responding to record signals to record onto a recording material.
(12) A method for ink-jet recording according to term (11), wherein said recording material is an information transmission sheet.
(13) A method for ink-jet recording according to term (12), wherein said information transmission sheet is a surface-treated sheet.
(14) An ink-jet printer which comprises being equipped with both a container receiving the water-based magenta ink composition according to any one of term (6) or (8) and a container receiving the water-based cyan ink composition containing water-soluble metal phthalocyanine dyestuff.
(15) An anthrapyridone compound or the salt according to term (1), wherein R1 is hydrogen atom or a lower alkoxycarbonyl group; R2 is methyl group: and B is hydrogen atom or a C1-C4 alkoxycarbonyl group.